Scrolling charts that are alternately wound back and forth between a pair of rollers are commonly used on chart recorders, advertising displays and other devices where information must be continuously or intermittently displayed. Typically, in the advertising display field for example, the scrolling chart comprises a plurality of banners. Each banner is a distinct image which is displayed by the device for a time until the next banner is to be displayed.
Previous display devices suffer from three distinct problems:
1) They do not provide for simple, fast and inexpensive removal, replacement, or otherwise not showing one or more of the individual banners in a scrolling chart without increasing wrinkling or causing other visual impairments; PA0 2) One device will not be configurable to custom sized, user produced banners without being prohibitively expensive; and, PA0 3) The command and control circuitry is expensive, awkward and of limited configurability with respect to individual banner display times and relative motor tensioning due to differently sized charts. PA0 1) Is capable of being configured to skip certain individual banners; PA0 2) Allows individual banners to be removed or replaced without removing and re-installing the rollers or carrier; PA0 3) Is capable of being configured to display custom sized banners mounted on charts and rollers of different lengths and widths; PA0 4) Has reduced circuitry hardware and increased flexibility of command and control of the rollers; and PA0 5) Minimizes the disadvantages described above such as banner lumps and wrinkles during display.
As for the first problem, in the past, charts have been formed by preprinting the banners end-to-end on a long continuous sheet. The problem with this approach is that no single banner can be easily removed, replaced or skipped when a particular advertiser wishes to cease displaying that banner.
Changing a single banner was a labor intensive, time consuming process requiring removal of the rollers from the display device, cutting out the offending banner, splicing in the new banner, and reinstalling the rollers. Splicing fixtures were developed allowing replacement while the rollers remained installed; however, replacement was still time consuming. It required significant care and skill to ensure proper banner positioning, alignment and proper placement of any control markings which inform the scrolling device where a banner begins and ends.
One solution to the interchangeability problem involved attaching individual banners together end-to-end to form a long continuous sheet. Here, durability and proper alignment became the overriding problem. A high degree of skill and time were still required to make an adequate interchange. Displays using this approach tended to be expensive, more complicated and less reliable because the means for attaching the banners to each other had to be rugged and precise to maintain proper alignment.
Another solution involved using pockets or other containment envelopes permanently formed on a web style carrier into which banners are inserted. From a mechanical standpoint, pockets formed from multiple layers of material attached together are generally incapable of being rolled onto a roller without creating large wrinkles or lumps in the multiple layers which, in turn, causes alignment problems. This is due to the difference in circumference of the various layers as they are wound onto a roller and the fact that the layers are attached to each other at the endpoints. Inserting a banner inside a pocket adds a third layer between the pocket layers which further compounds the problem by increasing the radial difference between the wound layers, further encouraging lumps and wrinkles.
Using resilient materials such as soft vinyl fabric to form the pockets does allow outer layers to stretch and inner layers to compress. However, as the material stretches longitudinally, its width tends to contract, like a rubber band. Similarly, as it is compressed, the width will expand. The net effect is that bulges and wrinkles are still formed.
In general, the use of larger diameter rollers will proportionally reduce the problem, but the problem still exists. Similarly, using dissimilar materials for the front and back layers of the pocket offer only moderate improvement. For example, one may use relatively stiff plastic for the inner layer and soft vinyl for the outer layer. The resilient outer vinyl will stretch as it is wound and contract during display. This may work well in the short term, however, after being repeatedly wound and displayed, the vinyl will relax, creating a loose front surface that encourages lumps and wrinkles.
Therefore, the use of pockets will cause wrinkles or lumps when rolled up and/or wrinkles, lumps or otherwise unacceptable optics when displayed flat.
Another solution disclosed by Aiken in U.S. Pat. No. 5,174,055 involves attaching removable banners to a web style carrier. Again, differences in the winding circumference causes bumps or bulges during display. Although front and back transparent guide sheets placed across the viewing window tend to minimize the viewable bulges by forcing them to the trailing side of the window, they are not eliminated, and the displayed portion of the banner is still not planar while in view. Increased cost and the inconvenience of threading the web through the guide sheets during banner or scroll replacement limit the effectiveness of this solution.
Another solution disclosed by Mazzocco, Sr. in U.S. Pat. No. 3,510,973 involves attaching removable banners to permanent sliding attachment points mounted on a web style carrier allowing relative longitudinal displacement between banner and web (See Mazzocco Column 5, lines 3-26). One problem with this approach again involves wrinkling since the fastening strips or button-like tabs will not lie completely flat when wound onto a roller. Increased cost results since the button-like tabs must be made rugged enough to allow the repeated sliding and banner interchanges. In addition, the banners themselves must be made rugged so that the slots for the tabs do not wear through. In this field, ruggedization is synonymous with expense. Further, this approach causes scraping between the banner and web. Any dust or dirt caught between the layers will quickly cause scratches to the banner surface reducing its aesthetic appeal.
Accordingly, there is a need for an inexpensive device for adequately displaying, with a minimum of wrinkling, banners which may be simply and quickly interchanged, removed altogether or skipped.
As for the second problem, there is no industry standard size for banners. Often times, banner size varies according to many factors such as budget, the subject matter of the display, and its location in a particular venue. Previous devices such as disclosed by Singer (U.S. Pat. No. 3,726,031) provide a specific enclosure requiring specific banner sizes. Although both Shettleroe (U.S. Pat. No. 4,862,614) and Simson (U.S. Pat. No. 5,493,802) provide some flexibility in the vertical and horizontal dimensions respectively, it is somewhat limited. Displaying banners with dimensions falling outside the limited range of these devices incurs the cost of buying or building a new device of a different scale. Therefore, there is a need for a banner display apparatus having greater flexibility in banner size.
As stated above, the third problem involves the relatively expensive command and control circuitry provided in current scrolling display devices. Simson et al., U.S. Pat. No. 5,410,330 discloses circuitry designed specifically for controlling the variable motor speeds required during the display of a roller based scrolling chart display. However, this circuitry has limited configurability with respect to roller speeds and display times per banner. Also, in general, the cost of manufacturing a circuit board and soldering components generally increases with the number of components used. In addition, a circuit made up of numerous discretely manufactured electronic devices is usually less reliable than those circuits requiring less discrete devices. Also, increasing the amount of hardware increases power consumption, which in turn may increase the number and cost of discrete devices. Accordingly, there is a need for an inexpensive scroll display apparatus which uses a minimum of hardware while providing greater command and control flexibility.